State Assemblyman John Wisniewski (D-Middlesex) said that if the review, led by Randy Mastro of the Los Angeles-based law firm Gibson, Dunn & Crutcher, was truly independent, both the firm and Christie should have no problem releasing to the public all of the supporting material.

"If it’s truly an unbiased report, there shouldn’t be any invocation of attorney-client privilege because that privilege belongs to the client, not to the attorney," Wisniewski said. "If the client is saying don’t use this information, it calls into question the objectivity of the report."

The law firm was retained by the state Attorney General's Office in January to conduct an internal review of the governor's office. The work reportedly cost more than $1 million, though neither Christie nor Mastro have commented on the exact cost.

The Attorney General's Office is representing the state in federal civil lawsuit that has been filed on behalf of a number of business owners who said they were harmed by the lane closings. But Wisniewski said regardless of who pays the bills, the governor's office was the intended client of the firm and would have the right to waive privilege.

"If this is to be treated seriously as a true report, there ought to be an explanation as to what, if anything, is withheld under some type of privilege, what the privilege is and why it’s being withheld," Wisniewski said.

He added that he intends to reconvene the committee this week to discuss the request.

Asked if the governor's office would release all of the documents related to the review, a spokesman, Kevin Roberts, provided a statement from Mastro saying, "Consistent with the governor’s pledge, the findings of the Gibson Dunn investigation were made public in a 345-page report, along with hundreds of supporting exhibits."

"The governor's office is fully cooperating with the U.S. Attorney’s Office's investigation, and in that regard, has not publicly released accounts of interviews conducted in connection with the Gibson Dunn investigation," Mastro said. "If the joint committee chooses to issue further subpoenas, the Governor's Office will review and respond to them at that time."

Joseph Hayden, a prominent New Jersey defense lawyer, said "there is a serious issue" as to whether Christie can claim attorney-client privilege given that scores of documents and interviews have been used as the basis of the report that has been made public.

“It will be argued that somebody can’t selectively assert a privilege," Hayden said. "If you turn over documents and interviews and they are used in a report that is made public, then there will be a serious legal challenge saying that those same documents and interviews can't be claimed to be privileged after they’ve been referred to in the public report.”

He added that if the governor's office or the Attorney General's Office claims the privilege, the committee will probably take the matter to court.

Michael Ambrosio, an ethics professor at Seton Hall law school, said the governor might also try to claim the government-process privilege or executive privilege.

Christie could argue the report was commissioned to reform internal policy and make sure a problem such as the lane closings does not occur again, Ambrosio said, allowing him to invoke the the government-process privilege.

Christie might make similar arguments in asserting executive privilege, he said, contending that records related to the review must be locked away “to provide some assurance that the deliberative process for determining executive policy is not unduly impeded.”